Ionization and Electronegativity

1.  How much energy is required to remove the most loosely bound electron from a neutral atom of carbon in the gaseous phase?

• 1. 801 kJ/mol  

• 2. 1086 kJ/mol

• 3. 1251 kJ/mol

• 4. 1000 kJ/mol

Answer explanation

Energy is required to remove electrons is ionization energy. Look it up for C in Table S

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2. Which element has an atom with the greatest attraction for electrons in a chemical bond?

• As

• N

• Bi

• P

Answer explanation

Attraction for electrons is electronegativity. Look up in Table S for each, N is the greatest.

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From which of these atoms in the ground state can a valence electron be removed using the least amount of energy?

• 1. nitrogen

• 2. carbon

• 3. oxygen  

• 4. chlorine

Answer explanation

"Removed using the least amount of energy" is referring to ionization energy. Look up each in Table S and Carbon is the lowest.

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 4. As the elements in Period 2 of the Periodic Table are considered in order from left to right, which property generally decreases?

• 1. A. atomic radius

• 1. B. electronegativity

• 1. C. ionization energy

• 1. D. nuclear charge

Answer explanation

Radius decreases across because the higher atomic number (protons) gives stronger attraction. Because of this the other 3, ionization energy, electronegativity and nuclear charge (protons) all increase across a period.

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5) Which trend is observed as the first four elements in Group 17 on the Periodic Table are considered in order of increasing atomic number?

• 3. Electronegativity increases.

• 3. First ionization energy decreases.

• 2. The number of valence electrons increases.

• 3. The number of electron shells decreases.

Answer explanation

Down a group, the ionization energy decreases as the atom gets larger due to more shells, the electrons are more loosely held.

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Which 2 characteristics are associated with metals

• 1. low first ionization energy and low electronegativity

• 1. low first ionization energy and high electronegativity

• 1. high first ionization energy and low electronegativity

• 1. high  first ionization energy and high electronegativity

Answer explanation

Metals tend to be larger and have low electronegativity and low ionization energy. This makes sense as they have fewer than 4 valence electrons and want to lose electrons to meet the octet rule.

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7)Which element in Group 18 of the Periodic Table has the highest first ionization energy?

• Krypton
• Argon
• Neon
• Helium

Answer explanation

You can look up in Table S, or know the trend that as you go down a group ionization energy decreases as more shells are added.

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Compared to the valence electrons of a nonmetallic atom, the valence electrons of a metallic atom are generally

• 1. fewer in number and less strongly held 

• 1. fewer in number and more strongly held 

• greater in number and less strongly held 

• 1. greater in number and more strongly held

Answer explanation

Metals have less than 4 valence electrons. They also have lower ionization energy which means that they hold their electrons less strongly. This is because they tend to be larger atoms and they lose Their electrons.

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9) Which of the following Group 2 elements has the lowest first ionization energy?

• 1. Be

• 2. Mg

• 3. Ca

• 4. Ba

Answer explanation

Use Table S, or know the trend IE decreases down a group as shells are added.

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10)As elements of Group 1 of the Periodic Table are considered in order from top to bottom, the ionization energy of each successive element decreases. This decrease is due to

• 1. decreasing radius and decreasing shielding effect 

• 1. decreasing radius and increasing shielding effect 

• 1. increasing radius and decreasing shielding effect 

• 1. increasing radius and increasing shielding effect

Answer explanation

Down a group radius increases as more shells are added. The shells act as "shields" against the attraction of the + charged nucleus, so the more shells the higher the "shielding effect."

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